In the final battle scene, several UH1 ("Huey") helicopters are shown firing Gatling guns and rockets into the battle. While many Hueys were unofficially modified by the ground crews to carry weaponry early in the Viet Nam conflict, the officially armed Huey, the UH1-C, actually wasn't introduced until mid-1966, several months after the battle at La Drang. Earlier Huey versions, which often did have door gunners, lacked the power and other modifications necessary to carry the types of weaponry shown in the movie. So, it is very unlikely that any Hueys involved in this battle would have had heavy guns or rockets.
In the scene where the soldiers are celebrating being sent to war, the Sam Moore and Dave Prater Jr. song "Hold On, I'm Coming" is playing at the party. This song was actually not released until five months after the battle of La Trang, in March 1966.
Joe Galloway's Nikon camera shown throughout the movie is a model "F Photomic FTN", first sold in Sept. 1968, but it was November 14, 1965 at 10:48 a.m., when Lt. Col. Hal Moore and his young troopers touched down at Landing Zone X-Ray in the Ia Drang.
When helicopters are landing or taking off, the sound effects are that of turbine engine RPM being increased or decreased as during engine start-up and shutdown on the ground. RPM is relatively constant during takeoff and landing. (This seems to be a common mistake in many films using helicopter sound effects.)
When the scene Lt. Col. Nguyen Huu An was telling his soldiers about their final attack, but the Vietnamese quote doesn't match the subtitle. If you listen carefully, you can hear it is exactly the same dialogue as when Lt. Col. Nguyen Huu An is sitting on the grass, speaking to himself.
In the beginning, the French Group Mobile 100 is ambushed and killed to the last man. In reality, the group was ambushed several times and in all of them, they were able to escape, though only after suffering severe casualties.
The conversation between SGM Plumley and Joe Galloway regarding his status as a non-combatant did not take place as shown in the film. The conversation actually took place more than a week earlier, and it was between Joe Galloway and an Army Special Forces Officer, Major (later Colonel) Charles Beckwith. Joe Galloway arrived with in the Ia Drang with an M-16.
In the opening scene that depicts the destruction of Groupement Mobile No.100, the officers are shown wearing képis, implying that they are members of the Foreign Legion. However, there were no Legion units present. GM 100 consisted of the 1st and 2nd Korea Battalions, Battalion de Marche of the 43rd Colonial Infantry and the 2nd Group of the 10th Colonial Artillery.
In the opening scene, French troops are shown with their beret insignia on the left side of their forehead. In reality, and contrary to most countries in the world, French soldiers have their insignia on the right side of their forehead.
SPOILER. The air strikes that supported the bayonet charge (to clear the area around the landing zone toward the end) were done by fixed-wing A-1E Skyraider aircraft rather than the Huey helicopters flown by Snake Crandall and Too Tall Freeman. It would have been impossible for the ground crews to change the configuration of the Hueys from "Slick" (troop carrier) to "Hog" (gunship) and back in the time frame depicted, especially with the nearly nonstop flying that Crandall and Freemen did.
Contrary to what's shown in the movie, Lieutenant Henry Herrick and 2nd Platoon did not recklessly charge after a lone NVA soldier, but were in fact ordered to advance out to the flank by Captain John Herren and did so in a disciplined manner. At one point, when coming to the clearing shown in the film, Herrick stopped and radioed back on whether or not he should continue through it or go around it, which was when he and his men were attacked by the NVA.
It was also Herrick's platoon that inflicted the first casualties on the NVA in said attack, not the other way around as shown in the movie.
In the film credits the following appears "With special thanks to: ...And the 3RD Ranger Training Battalion..." No such unit exists or ever has. There is a 3RD Battalion, 75TH Ranger Regiment and 4TH through 6TH Ranger Training Battalions.
As pointed out during the beginning of the movie. The battalion was issued "a new weapon" This would imply that they were issued the original variant of the M-16 rifle. During the battle scenes you can see several rifles that have a Forward Assist. This was not on the original variant of the M-16, it was introduced on the next model. The M-16 A-1.. The Forward Assist is used to help seat a round into the chamber and is still used on the M-16/M-4 rifle.
Greg Kinnear's character, Major Bruce Crandall, and Mark McCracken's character, Captain Ed Freeman, are helicopter pilots; and wear the branch insignia US Army Corps of Engineers. This is not incorrect. Army Aviation did not exist as a branch from 1947, when the US Air Force separated from the Army, to 1983 when a new Army Aviation Branch was created wearing the old Army Air Force branch insignia. From 1947 to 1983, Army aviators were trained in and designated as belonging to other branches prior to entering flight training, and wore their basic branch insignia even when assigned to flying duties.
In the final battle scene, an NVA soldier is manning a German MG34 machine gun. Although used extensively during WW2, the MG34 was captured from the Germans and used by many combatants, notably French and Russian and saw service life in the PAVN, Korean People's Army and Viet Cong.
When Joe Galloway helps defend the aid post, as he aims his M16 it can appear that there is no round chambered, since the bolt is in the forward position. However, the M16 fires from the closed-bolt position, so when a round is chambered, the bolt will be forward.
When Barry Pepper's character Joe Galloway puts his camera down and picks up a rifle to help defend the position, he places the camera on the ground at the base of a small tree. Later, when he goes to retrieve the camera and start taking photographs again, the camera is hanging from a tree branch. However, a fair amount of time passed and significant activity took place around that area, so anyone could have moved the camera and its changed location is consistent with this.
When Moore and his soldiers capture a North Vietnamese Army deserter and ask him where his friends are, he supposedly says this is a base camp for the whole division; four thousand men (which was in the script). While in translation the words about the base camp are correct, the Vietnamese word (muoi ngan) he says is actually ten thousand, not four thousand.